Inflators are devices that screw threadedly engage gas cartridges such as CO.sub.2 cartridges, and which contain a mechanism for puncturing the gas cartridge when it is desired to achieve rapid inflation of an inflatable article. The mechanism includes a pivotally mounted bell crank that is rotatably mounted about a pivot shaft carried by the inflator. Pulling a lanyard effects pivoting of the bell crank and a part of the crank cammingly engages a cartridge-piercing pin and drives it into the cartridge to thereby release the gases therefrom.
One problem with this type of inflator is that the force required to rotate the bell crank about its pivot shaft is not great; even a slight tug on the lanyard may result in the piercing of the cartridge. For example, a small tug by an airline flight attendant performing a demonstration may activate an unprotected inflator.
Accordingly, the art has developed a frangible plastic rivet that extends through the inflator housing and the bell crank to tie those items together and to thereby guard against inadvertent piercing of a cartridge. Just as in metal rivets, the plastic rivets initially have a single head and shaft; the shaft is inserted into a bore formed in the inflator and bell crank and a second head is then formed on the protruding end of the shaft. Obviously, the forming of the second head is time-consuming and expensive.
Thus, there remains a need for an inflator safety lock of improved design, but the prior art, taken as a whole, neither teaches nor suggests how to improve the rivet construction now in use.